Research On Light-weight Design Of 750kW Wind Turbine Gearbox Housings

In recent years,with the energy consumption increased year by year,environmental problems occur frequently,which makes the world pay more attention on the use of wind energy,and global wind power industry develop rapidly.Wind turbine gearbox(WTG)is the core component in the wind power equipment,which bears the harsh work conditions in the daily operation.Gearbox housings are deformed under loads,it will take a significant effect on bearing's running and gear's meshing.And the deformation will affect the performance and lifetime of the whole gearbox further.Based on the development of 750 kW WTG of Dalian Huarui Heavy Industry(DHHI),this paper researches the structure optimization of the housings,under the premise of maintaining or lifting the static performance of WTG.This research can improve product performance significantly,reduce product manufacture and maintenance costs.The main contents are as follows:(1)This paper explain the basic principles of finite element analysis technology,and the principle,mathematical model,algorithm of topology optimization and Sizing Optimization in structure optimization.And explain the software HyperWorks,OptiStruct used in the optimization process.(2)Finite element static analysis(FESA): use CAD software to build all housings(main housing,rear housing,rear cover)3D models and simplified,import the model into HyperWorks to establish a FESA model.Ignore the mounting bracket stiffness,use the non-flexible bearings to constrain.Then,based on the two kinds of extremely load conditions to solve the FESA model,and the analysis results is used as the reference for subsequent structure optimization.(3)Conceptual model design: According to the FESA results,the performance evaluation indexes of housing optimization are proposed.Based on those indexes,the topology optimization model is established in two cases: one is the minimum weighted compliance as the objective function,the volume ratio is the constraint;the other is the minimum mass as the objective function,the compliance is the constraint,taking the various manufacturing technology constraints into account for topology optimization of the three housings.Finally,the conceptual model is established according to the topology density contour plot.(4)Strength and structure design: Based on the new topology optimization structure,establish the Sizing Optimization model with the shell element thickness as the design variable,the displacement of the center point of the rear cover bearing hole as the constraint,and the minimum mass as the objective function.And the final design is determined based on the Sizing Optimization results.Finally,through the FESA,compared with the initial design from the perspective of displacement,stress,mass and other aspects.Compared with the initial design,the housings overall loss weight 9.73%,which including main housing 2.38%,rear housing 12.52%,rear cover 12.03%.In the static characteristic,under the work condition DLC1.4,the maximum displacement is reduced by 27.27%;And the axis misalignment of rear housing – rear cover is kept constant;The maximum stress is reduced by 11.58%.Under DLC2.1,the maximum displacement is reduced by 12.19%;The axis misalignment increased by 0.5%;The maximum stress decreased by 8.51%.The results show that the weight of housings is reduced significantly when the static characteristics are improved,and the purpose of this research is achieved.